(CNN) – It will be an uphill, obstacle ridden battle to convict the white officer, Darren Wilson, who shot unarmed, black teenager Michael Brown, according to legal experts.

"Often jurors are extremely sympathetic to police officers. They think even if he made a mistake, he's got the hardest job in the world. So they often want to cut police officers some slack," said former federal prosecutor Paul Butler, professor with Georgetown University Law School.

Meanwhile, there have been varying eye witness accounts of the shooting.

"Eye witness testimonies are notoriously unreliable," Butler said. "When we look at the false conviction cases, it's often because of eyewitness testimony that was just flat out wrong," he says.

The racial make up of the grand jury - nine white jurors and three African American jurors - will also factor into the decision handed down against Officer Wilson.

"We know from people's life experiences from the polls that we're seeing about Ferguson that African-Americans and white people are looking at this case very differently," said Butler.

"African-Americans often are much more suspicious of the police. They're less likely to believe the police. In part because they've had more negative experiences with the police," he said.

"We would like to think that race doesn't matter, but even in cases like this especially in cases like this race matters," he said.